C dynamic memory allocation for table of structs
- by JosiP
Hi here is my code. I want to dynamincly change no of elemnts in table with structs __state:
typedef struct __state{
long int timestamp;
int val;
int prev_value;
}*state_p, state_t;
int main(int argc, char **argv){
int zm;
int previous_state = 0;
int state = 0;
int i = 0;
int j;
state_p st;
//here i want to have 20 structs st.
st = (state_p) malloc(sizeof(state_t) * 20);
while(1){
previous_state = state;
scanf("%d", &state);
printf("%d, %d\n", state, previous_state);
if (previous_state != state){
printf("state changed %d %d\n", previous_state, state);
// here i got compile error:
main.c: In function ‘main’:
main.c:30: error: incompatible type for argument 1 of ‘save_state’
main.c:34: error: invalid type argument of ‘->’
main.c:34: error: invalid type argument of ‘->’
save_state(st[i],previous_state, state);
}
i++;
}
return 0;
}
I suppose i have to change that st[i] to smth like st+ptr ? where pointer is incermeting in each loop iteration ? Or am I wrong ? When i change code: initialization into state_p st[20] and in each loop iteration i put st[i] = (state_p)malloc(sizeof(state_t)) everything works fine, but i want to dynammicly change number of elemets in that table.
Thx in advance for any help